Piston pumps are known in which a piston is reciprocally slidable into and out of an open end of a piston chamber forming member to dispense fluid and in which inwardly of the piston, a one-way valve is provided to restrict flow through the piston chamber. For example, such piston pump assemblies are disclosed in U.S. Pat. No. 5,282,552 to Ophardt, issued Feb. 1, 1994, the disclosure of which is incorporated herein by reference.
A disadvantage of such previously known devices is that the one-way valve provided within the inner end of the piston chamber forming body is a separate element which must be separately manufactured, handled and assembled with increased cost.
Fluid dispensers are known in which fluid in a reservoir container or bottle is to be dispensed from the bottle out of an outlet from the bottle via a pump mechanism secured in the outlet of the bottle. Such pump mechanisms are known in which a piston is coaxially slidable into a piston chamber forming member to dispense fluid from the bottle. Many known piston mechanisms provide an arrangement in which the piston can manually be removed from the piston chamber forming member and the bottle can then be refilled.
Unauthorized refilling of bottles can provide problems as to warranties and ensuring product quality and that product may be dispensed within a suitable product life.
Known pump mechanisms include those disclosed in U.S. Pat. No. 5,676,277 to Ophardt issued Oct. 14, 1997 and U.S. Pat. No. 6,601,736 to Ophardt issued Aug. 5, 2003, the disclosures of which are incorporated herein by reference.